Buggy code:
public class UnconditionalFlowInfo extends FlowInfo { public static class AssertionFailedException extends RuntimeException { private static final long serialVersionUID = 1827352841030089703L ; public AssertionFailedException ( String message ) { } } public static final boolean coverageTestFlag = false ; public static int coverageTestId ; public long definiteInits ; public long potentialInits ; public long nullBit1 ; public long nullBit2 ; public long nullBit3 ; public long nullBit4 ; public static final int extraLength = 6 ; public long [ ] [ ] extra ; public int maxFieldCount ; public static final int BitCacheSize = 64 ; public FlowInfo addInitializationsFrom ( FlowInfo inits ) { } public FlowInfo addPotentialInitializationsFrom ( FlowInfo inits ) { if ( ( this ) == ( FlowInfo . DEAD_END ) ) { return this ; } if ( inits == ( FlowInfo . DEAD_END ) ) { return this ; } UnconditionalFlowInfo otherInits = inits . unconditionalInits ( ) ; this . potentialInits |= otherInits . potentialInits ; if ( ( this . extra ) != null ) { if ( ( otherInits . extra ) != null ) { int i = 0 ; int length ; int otherLength ; if ( ( length = this . extra [ 0 ] . length ) < ( otherLength = otherInits . extra [ 0 ] . length ) ) { for ( int j = 0 ; j < ( UnconditionalFlowInfo . extraLength ) ; j ++ ) { System . arraycopy ( this . extra [ j ] , 0 , ( this . extra [ j ] = new long [ otherLength ] ) , 0 , length ) ; } for ( ; i < length ; i ++ ) { this . extra [ 1 ] [ i ] |= otherInits . extra [ 1 ] [ i ] ; } for ( ; i < otherLength ; i ++ ) { this . extra [ 1 ] [ i ] = otherInits . extra [ 1 ] [ i ] ; } } else { for ( ; i < otherLength ; i ++ ) { this . extra [ 1 ] [ i ] |= otherInits . extra [ 1 ] [ i ] ; } } } } else if ( ( otherInits . extra ) != null ) { int otherLength = otherInits . extra [ 0 ] . length ; this . extra = new long [ UnconditionalFlowInfo . extraLength ] [ ] ; for ( int j = 0 ; j < ( UnconditionalFlowInfo . extraLength ) ; j ++ ) { this . extra [ j ] = new long [ otherLength ] ; } System . arraycopy ( otherInits . extra [ 1 ] , 0 , this . extra [ 1 ] , 0 , otherLength ) ; } <START_BUG> this . addPotentialNullInfoFrom ( otherInits ) ; <END_BUG> return this ; } public UnconditionalFlowInfo addPotentialNullInfoFrom ( UnconditionalFlowInfo otherInits ) { } public final boolean cannotBeDefinitelyNullOrNonNull ( LocalVariableBinding local ) { } public final boolean cannotBeNull ( LocalVariableBinding local ) { } public final boolean canOnlyBeNull ( LocalVariableBinding local ) { } public FlowInfo copy ( ) { } public UnconditionalFlowInfo discardInitializationInfo ( ) { } public UnconditionalFlowInfo discardNonFieldInitializations ( ) { } public FlowInfo initsWhenFalse ( ) { } public FlowInfo initsWhenTrue ( ) { } private final boolean isDefinitelyAssigned ( int position ) { } public final boolean isDefinitelyAssigned ( FieldBinding field ) { } public final boolean isDefinitelyAssigned ( LocalVariableBinding local ) { } public final boolean isDefinitelyNonNull ( LocalVariableBinding local ) { } public final boolean isDefinitelyNull ( LocalVariableBinding local ) { } public final boolean isDefinitelyUnknown ( LocalVariableBinding local ) { } private final boolean isPotentiallyAssigned ( int position ) { } public final boolean isPotentiallyAssigned ( FieldBinding field ) { } public final boolean isPotentiallyAssigned ( LocalVariableBinding local ) { } public final boolean isPotentiallyNonNull ( LocalVariableBinding local ) { } public final boolean isPotentiallyNull ( LocalVariableBinding local ) { } public final boolean isPotentiallyUnknown ( LocalVariableBinding local ) { } public final boolean isProtectedNonNull ( LocalVariableBinding local ) { } public final boolean isProtectedNull ( LocalVariableBinding local ) { } public void markAsComparedEqualToNonNull ( LocalVariableBinding local ) { } public void markAsComparedEqualToNull ( LocalVariableBinding local ) { } private final void markAsDefinitelyAssigned ( int position ) { } public void markAsDefinitelyAssigned ( FieldBinding field ) { } public void markAsDefinitelyAssigned ( LocalVariableBinding local ) { } public void markAsDefinitelyNonNull ( LocalVariableBinding local ) { } public void markAsDefinitelyNull ( LocalVariableBinding local ) { } public void markAsDefinitelyUnknown ( LocalVariableBinding local ) { } public UnconditionalFlowInfo mergedWith ( UnconditionalFlowInfo otherInits ) { } static int numberOfEnclosingFields ( ReferenceBinding type ) { } public UnconditionalFlowInfo nullInfoLessUnconditionalCopy ( ) { } public FlowInfo safeInitsWhenTrue ( ) { } public FlowInfo setReachMode ( int reachMode ) { } public String toString ( ) { } public UnconditionalFlowInfo unconditionalCopy ( ) { } public UnconditionalFlowInfo unconditionalFieldLessCopy ( ) { } public UnconditionalFlowInfo unconditionalInits ( ) { } public UnconditionalFlowInfo unconditionalInitsWithoutSideEffect ( ) { } }

Fix:
addPotentialNullInfoFrom ( otherInits ) ;